I’d argue that 3 is an implementation detail. If we’re serious about getting guns off the streets, then we need to make it worthwhile to trade them in.

As to 4 and 5, I’ll just say that not all shooting are “mass shootings” like we saw in El Paso. Chicago alone has something like 1500 shootings each year, many of which go unsolved. The article I linked says that the ATF gets 1000 gun trace requests per day and it takes an average of 4-7 days to compete one of them. That seems a bit slow to me, but I honestly can’t say what effect speeding that up would have on our ability to prosecute perpetrators of gun violence.